It's easy to monitor sounds. It's considerably harder to do it with video. I don't think a computer would be able to tell the differences between two similar videos, and would require human supervision. Due to the amount of cintent uploaded onto Youtube every day, there would be an insane backlog. This is why YT and many other companies (imgur and reddit, for instance) rely on the user to report violations of policy.

Quantum Vagina

Ein saw that someone left the gate open and decided to go for a walk. luckily someone nice picked him up, called the number on the tag to vet clinic, and I was able to get him back. Thats my early morning panic attack sorted.